The Guardian and Cleantech Group recently announced the Global Cleantech 100. This is the first ever list of this scale highlighting the most promising private clean technology companies around the world.  The Global Cleantech 100 recognizes companies at the forefront of cleantech innovation offering solutions to some of the world’s most pressing environmental challenges.  The final list represents the collective opinion of hundreds of leading experts from cleantech innovation and venture capital companies in EMEA, North America, India and China, combined with the specific input of an expert panel of 35, drawn from well-respected organizations such as Altira Group, Crossover Advisors, Deloitte, Emerald Technology Ventures, Google, Kleiner Perkins Caulfield & Byers, New York Stock Exchange, NGEN Partners, Nth Power, New Enterprise Associates, Sterling Communications, Tsing Capital and Vantage Point Venture Partners.

The panel decided on companies that are currently regarded as having the potential and likelihood to achieve high growth and high market impact. Their thoughts were then combined with insights from the Cleantech Network™, the de facto industry association of international clean technology investors, entrepreneurs, large corporations and other industry insiders. Some 3,500 companies were nominated/considered.

“The first ever Global Cleantech 100 shines a spotlight on which companies and which technology areas the global innovation community is currently most excited about, from a commercial standpoint,” said Richard Youngman, managing partner at Cleantech Group. “Although none of these firms are exactly household names, their innovations and the business acumen of their leaders and investors mean that they are likely to have high impact on our future. The Global Cleantech 100 companies, and many other worthy peer companies, stand to enable environmental sustainability and generate economic growth.”

Companies in energy sectors dominate the global list, with 74 of the final 100 focused on energy generation, infrastructure, energy efficiency, and storage. Diminishing oil and gas reserves, rising global demand for power, and fluctuating market prices have focused efforts on new, more efficient methods of creating and providing energy, and saving and storing it.

Ten of The Most Promising Solar Companies

Concentrix Solar
Freiburg, Germany
Product description: Concentrator photovoltaics

California, US.
Product description: Solar microinverters

G24 Innovations
Cardiff, UK.
Product description: Thin film solar cells

California, US.
Product description: Concentrating photovoltaics

Dresden, Germany.
Product description: Organic solar cell systems

Infinia Corporation
Washington, US.
Product description: Solar power generation

Kingston, UK.
Product description: Solar cells

Paris, France.
Product description: Installation and operation of residential and commercial solar power

London UK.
Product description: Solar energy consultancy for buildings

California, US.
Product description: Solar power system design, financing, installation, monitoring

View the full list of the most promising solar companies.

Five of The Most Promising Biofuel Companies

Amyris Biotechnologies
California, US.
Product description: Biofuels

Ballerup, Denmark.
Product description: Biofuels

Stockholm, Sweden.
Product description: Biofuels

Cobalt Biofuels
California, US.
Product description: Biofuels

Illinois, US.
Product description: Feedstock-flexible, syngas-to-ethanol platform

The Most Promising Wind Company
Trondheim, Norway.
Product description: Wind power

The Most Promising Wave Company
Marine Current Turbines
Bristol, UK.
Product description: Tidal power turbines for energy generation

Most Promising Geothermal Company
AltaRock Energy
California, US.
Product description: Engineered geothermal systems

View the full list of the most promising biofuel, wave, wind, tidal, and geothermal companies

The Most Promising Energy Efficiency Companies

Albeo Technologies
Colorado, US.
Product description: LED lighting

Uppsala, Sweden.
Product description: Glass

Cambridge, UK.
Product description: Smart energy service

New York, US.
Product description: Energy management

View All of The Most Promising Energy Efficiency Companies

The Most Promising Energy Storage Company

Bloom Energy
California, US.
Product description: Fuel cells

View The Full List of The Most Promising Energy Storage Companies

The Most Promising Recycling and Waste Management Company

MBA Polymers
California, US.
Product description: High value plastic recycling

View The Full List of The Most Promising Recycling and  Waste Management Companies

The Most Promising Transportation Company

Achates Power
California, US.
Product description: Clean diesel engines

View The Full List of The Most Promising Transportation Companies

The Most Promising Water and Wastewater Treatment Company

Danfoss AquaZ
Nordborg, Denmark.
Product description: Water treatment

View The Full List of The Most Promising Water and Wastewater Treatment Companies

View The Full Global Cleantech 100 List

© 2009 – 2011, Tracey de Morsella. All rights reserved. Do not republish.

Line Break

Author: Tracey de Morsella (323 Articles)

Tracey de Morsella started her career working as an editor for US Technology Magazine. She used that experience to launch Delaware Valley Network, a publication for professionals in the Greater Philadelphia area. Years later, she used the contacts and resources she acquired to work in executive search specializing in technical and diversity recruitment. She has conducted recruitment training seminars for Wachovia Bank, the Department of Interior and the US Postal Service. During this time, she also created a diversity portal called The Multicultural Advantage and published the Diversity Recruitment Advertising Toolkit, a directory of recruiting resources for human resources professionals. Her career and recruitment articles have appeared in numerous publications and web portals including Woman Engineer Magazine,, Job Search Channel, Workplace Diversity Magazine, Society for Human Resource Management web site, NSBE Engineering Magazine,, and Human Resource Consultants Association Newsletter. Her work with technology professionals drew her to pursuing training and work in web development, which led to a stint at Merrill Lynch as an Intranet Manager. In March, she decided to combine her technical and career management expertise with her passion for the environment, and with her husband, launched The Green Economy Post, a blog providing green career information and covering the impact of the environment, sustainable building, cleantech and renewable energy on the US economy. Her sustainability articles have appeared on Industrial Maintenance & Plant Operation, Chem.Info,FastCompany and CleanTechies.

  • Jerry Toman

    Due to the demographics of the “voters” who seem to have backgrounds spun-off from the semi-conductor industry or its venture-capitalist benefactors, it’s not surprising that these companies give top-billing to (themselves) companies involved in photovoltaic solar, with CSP as a distant second in the ratings, followed by wind, geothermal and other renewable technologies. They are trying to create a self-fulfilling prophesy because they either have a direct financial interest or that’s where there “know-how” resides.

    I think that if somehow sun were capable of shining 24/365 on these installations, nobody would or could challenge them in their assessment.

    But the fact of the matter is that for most of them, production approaching peak capacity only occurs for only about 6-10 hours a day–and far less during the winter above 45 deg. latitude, when power is most needed at that location.

    Storage of power as electricity, or indirectly as chemicals, is in it’s infancy at best. The most often cited is water electrolysis, followed by hydrogen storage, and then usage in fuel-cells, the combination of which isn’t very high in terms of cycle efficiency.

    CSP has the potential of extended a few hours further into the evening by hot storage of the thermal fluid, but the amounts required to be stored could be substantial.

    The easiest energy storage system is low-temperature thermal. Ground-assist heat pumps are an expample of long-term thermal energy storage. This thermal energy can be exploited in other ways, as will be seen.

    Nature, itself stores low-temperature thermal as CAPE in the air (lower troposphere) as Convective Available Potential Energy (CAPE) which is harvestable, and persists well into the evening hours during the summer. Nature also stores thermal in warms surface waters, and when these (oceans) overheat, it finds a convenient way of cooling them by producing a hurricane.

    How does one harvest this low-grade thermal energy?

    For the oceans, the technology known at OTEC (ocean thermal energy conversion) had cache many years ago. It depended on cycling a working fluid between the the warm surface water and a cold layer hundreds of meters below. Turns out the temperature difference of 30-40 F was not enough to give a Carnot efficiency greater than a few percent, once the delta T requirements through the heat exchangers were met.

    Nowadays, OTEC has morphed into the AVE (Atmospheric Vortex Engine) which has the advantage not rejecting heat into a cold reservoir of about 40 F, but into the tropopause which is at -50 F (average). This increases the “effective” temperature difference by an order of magnitude as compared to OTEC, and therefore, the theoretical efficiency is greatly increased.

    The Enviromission is an example of a project that would attempt to tap into this potential, but it is simply too cumbersome and fraught with risk, and can’t be built tall enough to take full advantage of the potential (hint: it doesn’t have a vortex).

    I hope to provide an article giving more details about how a much more efficient cousin of the E-M project could be integrated into schemes involving solar, wind or even existing fossil or nuclear-based technologies is forthcoming. Meanwhile those of you interested in a preview, can consult

    If the voters were a well-rounded collection of scientists who understood nature, and not just a collection of bankers, MBAs, etc., who only understand “money” (with a few semi-conductor physics-types in the mix) the outcome of the selection process might have been different. JJT

    • Tracey

      I was shocked that the overlooked so many in wind, geothermal and biotech. I would agree that it seems as if the panel were voting in their own interests, which hurts the legitimacy of the list.

  • Mark November

    The best solar technology is about to come from C.S.P. with its breakthroughs including the lowest cost to manufacture per watt combined with the highest reliabilty. Starting next year, its products will be the only economic choice for solar farms, residential and commercial rooftops.

    The other company that is not on this list is A.S., which has developed the technology that eliminates radioactive waste and eliminates the need for nuclear power reactors to make radioisotopes.

    Mark –

  • Tom Witkin

    Given the the level of renewable energy / clean tech activity in New England, interesting that only two area firms, Mascoma and Ze-gen – both biofuels related – are based there. Notable, too, that both are backed by Flagship Ventures. Partner, Jim Matheson sits on both boards.

  • Curtis Dyle

    This is an interesting list and well worth following, but I think it is premature to settle on any technologies yet. I encourage everyone to follow such list, but be cautious and skeptical about jumping onto any bandwaggon yet. I have been in the engineering world for 45 years now and have seen far to many “answers for everything” not pan out.

  • Earth Alive

    Earth Alive is a leading-edge manufacturer of low cost, high performing “Green” organic microbial cleaning solutions, from natural renewable resources. Save hot water, space, money & time. Reduce slip/fall accidents & training time.